Amid US-Mexico tension, defense chief aims to be calm voice

MEXICO CITY – U.S. Defense Secretary Jim Mattis is stepping into politically fraught U.S. relations during a visit to Mexico, seeking to add a calming voice on defense ties.

Mattis is meeting with senior government officials in the capital on the eve of Mexico's national Independence Day.

The relationship between Mexico and the United States has faced new challenges since the election of President Donald Trump, who referred to Mexican immigrants as criminals and rapists during his campaign.

Trump also has insisted Mexico must pay for a U.S. border wall. Mattis told reporters prior to arriving that he did not expect officials to ask him about the wall.